The test benches shown in Figure 1 are commonly used to run through the complete operating ranges of the drive components (battery, DC/AC converter, electric machine). The components highlighted in blue are the DC/AC converter (frequency converter) or the electric machine to be tested. The green-shaded components constitute the braking unit (electrical load machine) for keeping the test machine at a certain speed. The power supply, which is connected to the electrical network, is highlighted in yellow. For cost and safety reasons, projects often do without a real drive battery and instead use a battery emulator (red-shaded).
To cover the drive components of e-mobility in their diversity and performance class, from e-scooters to hybrid and electric vehicles to city trams, two test benches are currently being built or procured. The application areas and performance data are shown in Table 1. Completion of the medium-power test bench is expected shortly. The test rig is shown in Figure 2. The highest drive power test bed is expected to be commissioned by the end of 2021.
In addition to the described test benches for operating real electrical machines, a so-called e-machine emulator is in use. An electric machine emulator is capable of simulating electric machines with any (reasonable) parameters. It thus replaces the test object in Figure 1 with a power electronic component that behaves like the real electrical machine on the terminal side. Thus, for example, the functionality of the developed control algorithms can be validated in its universality without the presence of further real machines. With minimal effort, fault cases in electrical machines can be simulated and the reaction of the control algorithms can be evaluated.